Aurin dye.



UNiTnn siui' ns en' n ,TOFWCE.

MAX WEILER, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN VORllI. FRIEDR. BAYER & CO, 01: ELBERFELD, GERMANY. A CORPORATION OF GERMANY.

AURIN DYE.

Specification of Letters Patent.

Patented Dec. 13, 1910.

No Drawing. Original application filed April 2?, 1910, SerialNo. 557,950. Divided and this application filed August 12, 1910. Serial Np. 576,837.

To all whom it may concern:

Be it known that I, MAX of pl'iilosophy, chemist, citizen of the German Empire. residing at Elherfeld, Germany, have invented new and useful linprovelnents in New Dyes, of which the following is :1 sl'iecification.

This application whii plication of my application Serial No. 557950 relates to the production of a new dyesutl' of the aurin series, which is obtained by condensingv in the-presence of oxidizing agents methylene di ortho eresotin-ie acid ,With. pnrat-cresotinic acid; I

The new .dye is it red powder soluble in dilute caustic soda lye with n red-violet color, dyeing wool from acidbaths a violet shade after chroming on the fiber.

Iii-order to illustrate the new process more fully the following example is given, the parts being by Weight:95 parts of methylene-di-ortho-cresotinic acid and 50.5 part-s \VmLnn, doctor h is u divisional :ip-

of pura-eresotinio acid are stirred atfrom '20 to 45 C. together with 1500 parts of a strong sulfuric acid and the necessary quantity of nitrosyl sulfuric acid until the quantity of the dyestuif produced does no longer increase and the evolution of nitrogen oxide ceases. The product of the reaction is poured on ice and the dyestuif is filtered on.

i clniniz- The herein described new dyestufi' obtain- 

